<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>对同级标记应用margin负值</title>
<style type="text/css">
div{
	width:120px;
	height:48px;
	background:#0CF;
	float:left;
	opacity:0.7;
	border:2px solid #FFF;
	border-radius:50px;
	text-align:center;
	line-height:48px;
	color:#000;
}
.second,.third,.fourth{
	margin-left:-15px;                 /*将盒子的左外边距设置为负值*/
}
</style>
</head>
<body>
<div class="first">首页</div>
<div class="second">公司简介</div>
<div class="third">产品</div>
<div class="fourth">联系我们</div>
</body>
</html>
